The Institutional Flow Cytometry Core Facility is located at the University of Texas Health Science Center (UTHSC). It has been in existence for the past 20 years. The base of the lab is a 20 year old FACSstar Plus and a 2 year old FACSCalibur analyzer equipped with 2 lasers. The FACStarPlus is equipped with a 70-CR599-dye laser with far-red excitation and an Argon laser with a standard and UV laser lines. The Dye laser is 20 years old and clocked > 6,000 hours. The Argon laser is 6 years old and clocked 4,000 hours. The 2-laser combination allows for up to a 3-color sorting. The FACStarPlus sorter was upgraded through NIH SIG grant 6 years ago, in the context of an equipment upgrade to a TurboSort system capable of sorting 2 populations of cells at approximately 6,000 events/sec with a purity of approximately 95% and a yield of approximately 50%. The Facility has acquired a FACSCalibur cytometer/analyzer through state funds about 2 years ago. Currently, the facility operates at 90% of its capacity of sorting and analysis and serves UTHSC faculty and a number of affiliated institutions with a total of >40 users. Eleven major users have NIH grants totaling 4.7 million dollars/year in direct costs. The Major users are from the Medical School and the Graduate School with a total of >20 clinical protocols in cancer, diabetes, aging, cardiology and infertility. The basic science projects are in differentiation, drug-resistance, alcohol induced, oxidative stress, apoptosis, T-cell receptor immunity, aging and zebrafish models. The institution pays for the operator's salary and maintenance of the equipment. We propose to replace the current FACStarPlus sorter with the more advanced FACSVANTAGE SE model cell sorter. The requested FACSVANTAGE SE system is equipped with 3-lasers: An Argon 90-C laser with a standard and UV excitation lines; a Krypton 303 C laser, with laser lines at 406 to 415 nm and a multi line UV at 337.5 to 356nm; and a Helium Neon laser with a far red (633nm) excitation. The requested FACSVANTAGE SE system supports 6 fluorescence parameter and 2 light scatter parameters (8 detectors). This combination of lasers will allow analysis and sorting of up to 7-colors (9-parameters). The requested system is capable of sorting 4 different cell populations and the TurboSortPlus upgrade will allow high speed sorting of 25,000 events/sec. The FACSVANTAGE SE comes also with the FACS DiVa, AccuSort and AccuDrop devices which allow for 4-way sorting of up to 7-colors with increased yield of sorted cells to >80%, at 99% purity of each of the 4 sorted populations. The requested upgrade will update our outdated, slow and less flexible sorting capabilities to today's modern needs. The new equipment will also widen the user's base, save sort time, reduce costs for users and will render sorting affordable to new users, especially in cases where low frequency (<1%) cell populations are sorted.